#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
long long arr(int x,int y)
{
	long long num1 = 1;
	int t = x;
	while (x)
	{
		num1 *= y;
		y--;
		x--;
	}
	long long num2 = 1;
	for (int b = 1; b <= t; b++)
	{
		num2 *= b;
	}
	return num1 / num2;
}
int main()
{
	long long n = 0;
	scanf("%d", &n);
	long long num = 0;
	for (long long i = 1; i <= n; i++)
	{
		num += arr(i,n);
	}
	printf("%lld", num);
	return 0;
}